Broad-spectrum capture of clinical pathogens using engineered Fc-mannose-binding lectin enhanced by antibiotic treatment

Abstract

Background: Fc-mannose-binding lectin (FcMBL), an engineered version of the blood opsonin MBL that contains the carbohydrate recognition domain (CRD) and flexible neck regions of MBL fused to the Fc portion of human IgG1, has been shown to bind various microbes and pathogen-associated molecular patterns (PAMPs). FcMBL has also been used to create an enzyme-linked lectin sorbent assay (ELLecSA) for use as a rapid (<1 h) diagnostic of bloodstream infections. Methods: Here we extended this work by using the ELLecSA to test FcMBL’s ability to bind to more than 190 different isolates from over 95 different pathogen species. Results: FcMBL bound to 85% of the isolates and 97 of the 112 (87%) different pathogen species tested, including bacteria, fungi, viral antigens and parasites. FcMBL also bound to PAMPs including, lipopolysaccharide endotoxin (LPS) and lipoteichoic acid (LTA) from Gram-negative and Gram-positive bacteria, as well as lipoarabinomannan (LAM) and phosphatidylinositol mannoside 6 (PIM6) from Mycobacterium tuberculosis. Conclusions: The efficiency of pathogen detection and variation between binding of different strains of the same species could be improved by treating the bacteria with antibiotics, or mechanical disruption using a bead mill, prior to FcMBL capture to reveal previously concealed binding sites within the bacterial cell wall. As FcMBL can bind to pathogens and PAMPs in urine as well as blood, its broad-binding capability could be leveraged to develop a variety of clinically relevant technologies, including infectious disease diagnostics, therapeutics, and vaccines.

Modular biomaterials vaccine technology protects against multiple pathogens and septic shock

“…The broad-spectrum efficacy against MRSA and multidrug-resistant bacteria suggest that this technology could represent a new alterative to antibiotics in the post-antibiotic era. Importantly, given the broad spectrum PAMPs binding capabilities of FcMBL (14), this vaccine approach should also be effective against a wide range of fungal, parasitic and viral targets. Moreover, the modular nature of the technology, and the use of lyophilized components should make this vaccination particularly useful for global and one world health applications.…”

“…2A). To avoid this toxicity, we then captured the E. coli PAMPs from the lysate using FcMBLbeads (13,14). When FcMBL-bead-captured PAMPs containing an equivalent amount of PAMPs as the E. coli cell lysate (20.5 PAMP/mL vs 22.9 PAMPs/mL in lysate) was injected into rabbits ( Fig.…”

“…2E). We used the previously described sandwich ELISA-like assay (13,14) to quantify and equalize the total amount of captured PAMPs added to each vaccine in all following studies to ensure equivalent PAMP dosing in different experiments, and with different bacterial species. The ciVAX forms a subcutaneous depot with little signs of necrosis, and the MPS lasts for longer than 7 days and dissolves spontaneously by 37 days (Supplementary Materials Fig.…”

“…Our goal was to develop a broad-spectrum infection vaccine that is potent, durable and safe, using complex killed bacterial components that do not require cold chain storage, and that also can be used for ring vaccination in biothreat or pandemic emergencies, without having to first identify or isolate the pathogen. To address this challenge, we combined two technologies that are currently in clinical development for other applications ¾ a broad spectrum engineered opsonin known as Fc-Mannose Binding Lectin (Fc-MBL) (12)(13)(14) that rapidly binds to carbohydrate-containing PAMP antigens (including glycoproteins and glycolipids) expressed on the surface of over 120 different pathogen species and toxins, including some that are known to trigger innate immunity (e.g., lipopolysaccharide endotoxin; LPS) (15), and a biomaterial scaffold-based vaccine being used for cancer immunotherapy (16)(17)(18) ¾ to create a new composite infection vaccine technology (ciVAX) (Fig. 1).…”

Biomimetic Nanomaterial Strategies for Virus Targeting: Antiviral Therapies and Vaccines

“…Seiler et al have further explored the use of an engineered version of MBL that demonstrated improved pathogen capture in blood and urine samples. [111] Based on these findings, there has been ongoing progress to develop extracorporeal blood filters for virus particle removal applications as well. Tullis et al demonstrated that hemodialysis treatment using a hollow-fiber cartridge that contained antibody-functionalized agarose beads could effectively remove HIV-1 virus particles and viral proteins from cell culture media and blood.…”